Which means defense will make all the difference. Teams like Seattle and San Francisco have gotten this far because of their defense. Now's as good a time as any to trust their bread and butter.

Here's a look at the games where defense will provide an upset factor.

Seahawks vs. Falcons

Seattle has gotten to the playoffs on the heels of dominating defensive play. They rank No. 1 in the NFL in points allowed per game, and fourth in yards allowed per game.

The Hawks defensive unit was stifling down the stretch, allowing just 60 points over their last five games.

After a slow start against Washington last weekend, Seattle settled down and didn't allow any points past the first quarter—holding the Redskins to just 14 on the day.

But now the Seahawks have the unfortunate task of facing off against the Atlanta Falcons on the road.

The Falcon's offense averages 281.8 passing yards a game, and to make things worse Seattle pass rusher Chris Clemons will be out for the remainder of the playoffs.

Despite his winning ways over the last few weeks, Russell Wilson is no Matt Ryan, nor does he have the weapons to exchange offensive blows with the Falcons.

If Seattle is to win this game, it's got to be through the physical play of its corners. Shut down Roddy White and Julio Jones, and force Ryan to go over the middle to his tight ends.

The Falcons only average 87.3 rushing yards a game, meaning Seattle can lean back a bit up front. That will allow them better coverage in the flats on receivers such as Tony Gonzalez.

Despite Atlanta's versatility, there's still plenty of hope for Seattle in this game. If they play physical and stick to their guns, the Seahawks have a chance to pull out an upset.

Upset Prediction: Seattle 24, Atlanta 17

Texans vs. Patriots

When last these two teams met, New England dominated Houston 42-14. Now the Texans have to enter Foxborough again and hope for different results.

Despite his emergence as a top quarterback in the NFL, Matt Schaub is still no Tom Brady. Playing in his first playoffs, Schaub lacks the experience and weapons to keep up with the Pat's offense.

He'll need to fall back on his defense to give Houston an edge.

That starts with defensive lineman J.J. Watt, who is enjoying a prolific season. But Watt was a non-factor in these teams' regular season matchup, recording four tackles with no sacks or deflections.

But the Texans have a stud pass rush, racking up 44 sacks in the regular season. If everyone contributes they can find ways to knock Brady off balance.

Another positive note is the current play of cornerback Johnathan Joseph, who dominated Cincinnati receiver A.J. Green—who didn't have a catch in all of the first half—last week.

If Joseph can neutralize some of Brady's targets, the Houston defense could pave the way for a huge upset in New England.

Upset Prediction: Houston 24, New England 20

Packers vs. 49ers

Despite it's struggles last season, the Green Bay defense has rebounded well this season surrendering just 21 points and 336.8 yards per game.

The Packers played a strong game against the Vikings last weekend, allowing just 324 yards and 10 points. They'll need that same kind of performance this weekend against the 49ers.

San Francisco has one of the best defensive squads in the NFL, so the Packers can't completely rely on Aaron Rodgers for a win.

Not to mention the 49ers won the previous matchup 30-22, and that was at Lambeau Field.

Despite its rejuvenated defense, Green Bay has struggled against the run this season, allowing 118.5 yards per game to opposing running backs.

But the Packers showed new life against the Vikings, holding Adrian Peterson to under 100 yards.

Like Minnesota, San Francisco relies on its ground game for offense. They averaged 5.8 yards per carry against the Packers in that early season win, and feature one of the best rushing attack in football.

But if Green Bay can slow them down like they did Minnesota, it will make the Niners one dimensional. Once that happens, an upset should be easy pickings.

Upset Prediction: Green Bay 28, San Francisco 13

Baltimore vs. Denver

This should be the most straight forward of all the Divisional Round games. Peyton Manning comes alive in the playoffs, and he'll be aided by his own stud defense.

Baltimore is still struggling to get healthy, with it's biggest role players trying to get healthy.

Ed Reed and Terrell Suggs seem poised to play through the pain, and have managed some signs of life down the stretch. There's also Ray Lewis, who looks like a man on a mission in his final playoffs.

The only way the Ravens stand a chance against the Broncos is to come out and do everything they did against the Colts. Bring pressure, knock the quarterback off balance and force him into bad throws.

Seeing how much better Peyton is protected than Andrew Luck, that's easier said than done.